Answer:
Time to land on 11ft is 4.25 seconds
Step-by-step explanation:
Given
[tex]y = 300 - 16t^2[/tex]
Required
Solve for t when height is 11ft
This implies that [tex]y = 11[/tex]
So: substitute 11 for y in [tex]y = 300 - 16t^2[/tex]
[tex]11 = 300 - 16t^2[/tex]
Collect Like Terms
[tex]16t^2 = 300 - 11[/tex]
[tex]16t^2 = 289[/tex]
Express both sides as squares
[tex]4^2 * t^2 = 17^2[/tex]
[tex](4t)^2 = 17^2[/tex]
Take square roots of both sides (ignore negative)
[tex]4t = 17[/tex]
Solve for t
[tex]t = \frac{17}{4}[/tex]
[tex]t = 4.25[/tex]
Hence, time to land on 11ft is 4.25 seconds